• Journal of Microbiology and Biotechnology
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• v.24 no.7
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• pp.959-968
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• 2014

The changes in the ${\beta}$-glucosidase activity, total phenolic contents, isoflavone contents, and antioxidant activities during the fermentation of cheonggukjang by Bacillus amyloliquefaciens MJ1-4 with and without garlic were investigated. The levels of total phenolic and isoflavone-malonylglycoside, -acetylglycoside, and -aglycone contents increased, whereas the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activities and ferric reducing/antioxidant power (FRAP) assay results increased, but isoflavone-glycoside levels decreased during cheonggukjang fermentation. The levels of total phenolic and total isoflavone contents and the antioxidant activities were higher in cheonggukjang fermented without garlic (CFWOG) than in cheonggukjang fermented with garlic (CFWG) after 24 h of fermentation, but they were lower in CFWOG than in CFWG after 72 h of fermentation. In particular, the highest levels of total phenolic, daidzein, glycitein, and genistein were present at concentrations of 15.18 mg/g, $264.4{\mu}g/g$, $16.4{\mu}g/g$, and $31.1{\mu}g/g$ after 72 h of fermentation in CFWG, showing 82.89% in DPPH radical scavenging activity, 106.32% in ABTS radical scavenging activity, and 1.47 ($OD_{593nm}$) in FRAP assay, respectively. From these results, we suggest that the high antioxidant activity of CFWG might be related to the markedly higher levels of total phenolic contents, isoflavone-malonylglycosides, -acetylglycosides, and -aglycones achieved during fermentation.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.317-323
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• 2016

An isoflavone glucosidase that catalyzes the hydrolysis of isoflavone glucosides into glucose and corresponding aglycones was purified from Candida fermentati SI. The N-terminal sequence was determined to be GLNCDYCN. We designed degenerate primers on the basis of these amino acid sequences and successfully cloned the full structural gene sequence of the isoflavone glucosidase using inverse PCR. The exo-β-(1,3)-glucanase gene consists of 1227 base-pair nucleotides, encoding a 408-amino-acid sequence that shares 41–96% amino acid homology with other yeast exo-β-(1,3)-glucanases belonging to glycoside hydrolase family 5. The recombinant exo-β-(1,3)-glucanase was expressed in Pichia pastoris X-33, using a pPICZA vector system, and further characterized. The molecular mass of the purified exo-β-(1,3)-glucanase was estimated by SDS-PAGE to be 47 kDa. The optimal pH and temperature were pH 4.5 and 40℃, respectively. The K_m values of the purified exo-β-(1,3)-glucanase for daidzin and genistin were 0.12 mM and 0.14 mM, respectively. The V_max values of the purified isoflavone glucosidase were 945.03 U/mg for daidzin and 835.92 U/mg and for genistin.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.363-369
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• 2014

This study was conducted to investigate the quality characteristics of tofu prepared with addition of cowpea meal (CPM). Any significant difference of L-value between control CPM-O and treatment CPM-I, CPM-II and CPM-III could not be seen as addition ratio of CPM increases (p < 0.05). The b-value of CPM-III (75%) has shown the least value of 14.26, and it has decreased as addition ratio of CPM increases. The result of texture profile did not show any significant difference between control CPM-O and CPM-Iexcept in the case of cohesiveness. The pH range of treatments was 6.36~6.52, which showed no significant difference from controls. The values of turbidity were 1.46~1.81, which had increasing trend as addition ratio of CPM increases. The total bacterial count of CPM-III was $4.40{\times}10^2CFU/g$, which showed significant difference from the control. No Esterichia coli was detected in the control and the treatments. The result of sensory analysis of the treatment CPM-I did not show any significant difference from the control, which implied the treatment CPM-Iwas found to be suitable at the tofu making using byproducts of cowpea-jelly making. Isoflavone glycoside (IG) was contained more on the order of genistin, daidzin, and glycitin, and the content decreased significantly as addition ratio of CPM increases. The content of isoflavone-aglycone (IA) was less than IG, but showed similar behavior of addition ratio of CPM.

• Journal of agriculture & life science
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• v.50 no.4
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• pp.157-167
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• 2016

The changes of total phenolic and isoflavone contents and antioxidant activities in of brown soymilk fermented by Lactobacillus plantarum P1201 were investigated. The brown soymilk proliferated the cell growth and reached about 11.55log cfu/g after fermentation for 60hr, while pH and titratable acidity ranged from 6.25 to 4.03 and 0.18% to 1.03%, respectively. The total phenolic contents of brown soymilk slightly increased from 2.87mg/g to 2.98mg/g after fermentation for 60hr. The levels of isoflavone-glycosides and -malonylglycosides decreased, while the isoflavone-aglycone contents increased during fermentation of brown soymilk. In particular, the isoflavone contents was 38.30㎍/g, but increased the highest value of 84.31㎍/g after fermentation for 60hr. After then, it was slightly decreased after 60hr of fermentation. In addition, the levels of daidzein, glycitein and genistein among isoflavone aglycones were 24.12㎍/g, 25.25㎍/g and 24.71 ㎍/g, after fermentation for 36hr. The DPPH and ABTS radical scavenging activities and FRAP assay showed to be slightly increased during lactic acid fermentation of brown soymilk.

• Korean journal of food and cookery science
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• v.26 no.2
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• pp.214-219
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• 2010

In this study, phytoestrogen for the industrial production of soybean probiotics by lactic acid bacteria (LAB) was studied in a soybean extract. Soybean was fermented with LAB, Lactobacillus plantarum KCTC 3108 and Bifidobacterum longum ATCC 15707. The change in the content of various isoflavones (aglycone and glucoside) and the $\beta$-glucosidase activity in soybean during fermentation were investigated and shown to be dependent on the starter organism. Soybean extract powder fermented with L. plantarum showed the highest $\beta$-glucosidase activity and the greatest increase in the aglycone content. After 48h of fermentation, the contents of daidzin, genistin and glycitin in L. plantarum decreased from a mean initial levels of $83.03{\pm}2.17$, $168.13{\pm}8.17$ and $20.02{\pm}1.07$, respectively, to mean levels of $5.34{\pm}3.24$, $3.79{\pm}0.57$ and $1.87{\pm}1.09\;mg$/100 g. Whereas, after 48h fermentation, the contents of daidzein, genistein and glycitein increased from a mean initial levels of $8.09{\pm}0.78$, $11.20{\pm}0.84$ and $4.71{\pm}0.46$, respectively, to mean levels of $85.76{\pm}0.84$, $175.87{\pm}2.21$ and $22.41{\pm}0.91\;mg$/100 g. Taken together, these results suggested an increase of aglycones and decrease of glucoside in isoflavones occurred during fermentation, which coincided with an increase of $\beta$-glucosidase activity in the fermented soybean extract powder.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.63-69
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• 2007

Compositional components such as isoflavone, protein, oil, fatty acid, and free sugar in Korean vegetable soybeans were examined with four cultivars including Hwaeomputkong, Keunolkong, Mirang, and Danmi 2. In the isoflavone, Mirang cultivar showed the highest content ($967.1{\mu}g/g$), whereas Keunolkong was the lowest content ($535.9{\mu}g/g$). The malonylglucosides were the predominant isoflavone type followed by the glucoside, aglycone, and acetyl glucoside forms, respectively. In the protein content, Hwaeomputkong was the lowest (41.7%) and Danmi 2 was the highest (45.9%). The oil contents were 11.5 to 21.2% and Mirang cultivar was the lowest. The fatty acid compositions of the oil extracts exhibited that linoleic acid was the highest (33.6-42.5%), followed by oleic, palmitic, linolenic, and stearic acids. Whereas, oleic acid ($46.7{\pm}2.0%$) was more than linoleic acid ($33.6{\pm}1.3%$) in Mirang cultivar. In the free sugar contents, Hwaeomputkong cultivar showed the highest level and sucrose ($5.52{\pm}0.49%$) appeared to be most prevalent in vegetable soybeans.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.83-89
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• 2007

In our study, lactic acid bacteria (LAB)-fermented whey solutions were applied in the soybean soaking process to minimize bacterial contamination and to enrich the biologically functional components of isoflavone and $\gamma$-aminobutyric acid (GABA). Among the 11 LAB tested, Bifidobacteria infantis and a mixed culture (Lactobacillus acidophilus, Bifidobacteria lactis, and Streptococcus thermophilus; ABT-3) displaying the greatest $\beta$-glucosidase activity were selected to produce improved biologically functional soybean preparations. In the soybean soaking processing (without water spraying), the LAB-cultured 10% whey solution was used to soak and to ferment the soybeans and the fermented soybeans were finally dried by heat-blowing at $55^{\circ}C$. The processing conditions used in this study demonstrated that the final soybean product had a reduced contamination by aerobic and coliform bacteria, compared to raw soybeans, likely due to the decrease in pH during LAB fermentation. The aglycone content of the isoflavone increased up to 44.6 mg per 100 g of dried soybean by the processing method, or approximately 8-9 times as much as their initial content. The GABA contents in the processed samples increased as the processing time of soaking-fermentation proceeded as well. The soybean sample that fermented by ABT-3 culture for 24 hr showed the greatest increase in GABA content (23.95 to 97.79 mg/100 g), probably as a result of the activity of glutamate decarboxylases (GAD) released from the soybean or produced by LAB during the soaking process.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.108-111
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• 2005

Studies were conducted to develop new breeding resources using wild soybean (Glycine soja Sieb. & Zucc.) species. In 132 wild soybeans, the average crude protein content was $45.4\%$, ranged from $37.4\%\;to\;50.2\%$ and average crude oil content was $9.3\%$ showing lower than cultivated soybean. The average total amino-acids content was $19,214\;{\mu}g/g$, containing $252\;{\mu}g/g$ of methionine and $103\;{\mu}g/g$ of cysteine, a sulfur containing amino-acid. In ratio of individual amino-acids, the glutamic acid, methionine and cystein content was $16.1\%,\;1.3\%,\;and\;0.5\%$, respectively. The correlation between total amino-acid and sulfur containing amino-acid was not significant. Total isoflavone concentration was, on average, $1,105\;{\mu}g/g$ in wild soybean germplasm. As a result of comparison with total isoflavone and genestein contents, significant positive correlations were observed between total isoflavone and genistein concentration.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.460-465
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• 2006

This study was conducted to investigate the isoflavone contents including daidzein and genistein in soy sauces made with whole grain soybean Meju(WGSM), comparing with defatted Meju(DM) du.ins fermentation. Total isoflavone contents in 2 soy sauces made with DM, Control and product A, increased with period of fermentation and were 15 and 4.3 times higher after 180 days of fermentation than on the day before fermentation respectively. Meanwhile, 2 soy sauces made with WGSM, product B and C, had the highest amounts with $20.53{\mu}g/g\;and\;19.52{\mu}g/g$ of isoflavones on the day before fermentation respectively, and then decreased with fermentation time. High amounts of isoflavones were detected in 20 days of fermentation of soy sauce which made with WGSM and wheat Meju(product D). Daidzein was the largest amounts in isoflavone contents, regardless of total or free isoflavone types. The level of daidzein increased with fermentation time in 2 soy sauces made with DM, Control and product A, whereas 2 soy sauces made with WGSM, product B and C decreased with fermentation time, instead of increasing of genistein contents.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.202-211
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• 2016

This study evaluated the changes of phytoestrogen contents and antioxidant activities of soybean-powder milk (SPM) prepared from yellow soybean during fermentation with Lactobacillus plantarum P1201. In consequence, the levels of total phenolic and isoflavone-aglycone contents, ABTS and DPPH radical-scavenging activities, and FRAP assay values increased, while isoflavone-glycoside contents decreased during fermentation. The highest levels of daidzein, glycitein, and genistein were present in the Daepung SPM at concentrations of 177.92, 20.64, and $106.14{\mu}g/g$, respectively after 60 h of fermentation. Moreover, Daepung SPM showed the highest DPPH radical-scavenging activity of 48.54%, an ABTS radical-scavenging activity of 99.25%, and a FRAP assay value of 0.84 at the end of fermentation. The fermented Daepung SPM possessed highest isoflavone aglycone contents and antioxidant activities, which can be utilized for the development of functional foods.